Antireflection films are generally arranged on the outermost surfaces of display devices such as cathode ray tube (CRT), plasma display (PDP), electroluminescence display (ELD), and liquid crystal display (LCD) so as to reduce reflectance by using the principle of optical interference for the purpose of preventing contrast reduction and mirroring of images by the reflection of outer light.
These antireflection films can be manufactured by forming a low refractive index layer having an appropriate thickness on the outermost surface of a support, and in some cases by forming arbitrarily a high refractive index layer, an intermediate refractive index layer, a hard coat layer and the like between a support and a low refractive index layer. As the materials of a low refractive index layer, materials having the lowest possible refractive index are desired from the viewpoint of realizing a low refractive index.
Since used at the outermost surface, antireflection films are required to have functions as the protective film of display devices, e.g., high transmittance, high physical strengths (scratch resistance, etc.), chemical resistance, a dust-proof property, an antifouling property, and weather fastness (moisture and heat resistance, light fastness, etc.) are required.
Since antireflection films are generally disposed on the outermost surface, they are required to have high scratch resistance and an antifouling property. The techniques of the improvement of scratch resistance by using a fluorine compound having a polysiloxane structure in a low refractive index layer are disclosed in WO 2004/046247 A1. However, it is difficult to obtain sufficient scratch resistance with only the techniques disclosed in these patents.
It is also difficult to obtain sufficient antifouling property.